Bitcoin has set a new landmark in SegWit adoption, having just crossed the 30% rate.
With the 0.16.0 Bitcoin Core release, which introduced full support for SegWit, the network has seen a sudden jump from around 15% to over 30% nodes running SegWit in the time span of about 15 blocks (~ 150 minutes).
This shows that the Bitcoin network is still vibrant and demonstrates the power of individual nodes to shape the P2P network.
The number of SegWit transactions is also gaining ground, although a bit more slowly than adoption. This is expected, since users must explicitly create new addresses before sending/receiving BTC using SegWit.
At the time of this writing, the number of 0.16.0 nodes is just under 15%, with Bitcoin Core 0.15.1 still dominating the network with over 47% of nodes still running the legacy version.
Mempool size has also collapsed in the first few hours after the 0.16.0 release, as can be seen on this chart by Blockchain.info:
It is worth noting that, on February 25, the mempool was completely empty for several hours.
SegWit is currently required for Lightning Network (LN) to function. In theory, SegWit should not be mandatory for LN, but the channel creation could take a very long time and make the network unusable. Therefore, we expect to see a strong correlation between SegWit adoption and the expansion of the Lightning Network in the coming weeks and months.
Bitcoin continues to adapt to change, overcoming technical hurdles which, in the recent past, have been used to predict its defeat (flippenings and flappenings). Quite on the contrary, Bitcoin's capacity to adapt has been its strongest quality all along. Strong SegWit adoption after the 0.16.0 release is a very important step in Bitcoin evolution and will surely mark the beginning of a new batch of 2nd layer innovations, of which Lightning Network is just the more famous one.